Answer:
The required elasticity is
.
The demand is inelastic.
The required value of p for which total revenue is maximum is 178.5
Explanation:
Consider the provided function.
![D_p= 357-p](https://img.qammunity.org/2020/formulas/mathematics/college/cohq9izfxkwf0ns5hluazyaaerkg3vsay3.png)
![D_p=q= 357-p](https://img.qammunity.org/2020/formulas/mathematics/college/ackk6hgwec05sigmve6q6cp17y00esrzch.png)
Part (A) The elasticity
The elasticity of demand is:
![E_p=(p)/(q) \cdot (dq)/(dp)](https://img.qammunity.org/2020/formulas/mathematics/college/oeepj9bsa04gsyuk1w6d3qfoivwfvbo3zy.png)
![(dq)/(dp)=-1](https://img.qammunity.org/2020/formulas/mathematics/college/kkdn31bszrztu8rndbt5e9gek4u6tkx0jy.png)
But elasticity is always positive therefore,
![E_p=(p)/(357-p)](https://img.qammunity.org/2020/formulas/mathematics/college/sab05fl87iswcyvreipx6ckbhpphftzjbt.png)
Hence, the required elasticity is
.
Part (b) The elasticity at p=89, stating whether the demand is elastic, inelastic or has unit elasticity.
Substitute p=89 in above elasticity formula.
![E_(89)=(89)/(357-89)](https://img.qammunity.org/2020/formulas/mathematics/college/w6jfiyw02akei98ft2f25rxs3wdb96r5ua.png)
![E_(89)=(89)/(268)](https://img.qammunity.org/2020/formulas/mathematics/college/1a3lm03aaqozvlbdi121x01i3w9c8nny6j.png)
The above value is less than 1, therefore the demand is inelastic.
Part (C) The value(s) of p for which total revenue is a maximum (assume that p is in dollars).
For maximum revenue substitute E=1.
![1=(p)/(357-p)](https://img.qammunity.org/2020/formulas/mathematics/college/6wcnxcxbd4uhet14bcry0583uc4anvm05o.png)
![357-p=p](https://img.qammunity.org/2020/formulas/mathematics/college/2qyt2erd5hy5oh0eu8mu61vklaserfn24h.png)
![2p=357](https://img.qammunity.org/2020/formulas/mathematics/college/r3bltdi5jkxfl7w41rb059q2sahwyc3f7g.png)
![p=178.5](https://img.qammunity.org/2020/formulas/mathematics/college/gykhq4gznxgxy9k1au0daz2v0go7yu6dav.png)
Hence, the required value of p for which total revenue is maximum is 178.5